1. Field of the Invention
The present invention relates to a phosphor ceramic and a light-emitting device including the phosphor ceramic.
2. Description of Related Art
Conventionally, as a phosphor that receives blue light and emits yellow light, a YAG (yttrium aluminum garnet) based phosphor where cerium is contained has been known. When the blue light is applied to the YAG based phosphor, white light can be obtained by mixing the applied blue light and the yellow light that the YAG based phosphor emits. Therefore, a white light emitting diode that is capable of obtaining white light by covering a blue light emitting diode with a YAG based phosphor to mix blue light from the blue light emitting diode and yellow light of the YAG based phosphor has been known.
There has been proposed, as such a YAG based phosphor, for example, a phosphor ceramic plate whose dopant (cerium) concentration and thickness are adjusted so as to realize the targeted luminescent chromaticity (ref: for example, Japanese Unexamined Patent Publication No. 2010-27704).